Referring to FIG. 1, in the prior art quartz bulb, a light shielding unit 2 is installed in a lampshade 1. The light shielding unit 2 has a cover portion 3 for shielding an upper side of a light source. Only light from lateral side is left. Thus light is refracted from the inner surfaces of the lampshade 1 and then is dispersed on the periphery of the lampshade 1. However the design of the light shielding unit 2 will make the manufacturing process tedious and some of the light is shielded. Therefore, the strength of the light is weakened.
In another prior art, the light emitted from the lateral side of a light source is strengthened. In one prior art, a light guide is installed at an upper side of a metal cup. An inner side of the light guide is formed as a cambered surface. A lower side of the light guide is formed as an inclined surface for refracting or dispersing light from LED (light emitting diodes) so that by the design of the inner inclined surface and cambered surface of the light guide will make the light to completely reflect. Thus light is dispersed to a periphery of the light guide so that the lateral side is lighter. However this can not provide for far distance emission.
Therefore, there is an eager demand for a novel design which provides a far place emission and removes flash from the illumination.